This IDDRC is a collaboration of the Children's Hospital of Philadelphia (CHOP) and the University of Pennsylvania (Penn). This renewal application requests support for six core units and three new program development (NPD) projects. The cores are: (1) An Administrative Core (Core A) that provides overall management, including (i) all educational programs, (ii) monthly lecture series, (iii) the NPD projects, and (iv) the Mid-Atlantic Research Consortium, a novel venture that merges physical and intellectual resources of the IDDRCs at Penn, Johns Hopkins University, and Children's National Medical Center;(2) A Biostatistics and Bioinformatics Core (Core B) that provides consultation for study design, statistical analysis, and bioinformatics/genomics;(3) A Molecular Genetics Core (Core C) that provides a centralized facility for DNA sequencing, fluorescent fragment analysis, mutation detection with cosmig contigs, screen of YAC libraries, quantitative PCR analysis, and gene mapping, etc.;(4) An Analytical Neurochemistry Core (Core D) that provides expertise and support with regard to biochemical analyses, including (i) the study of second messenger systems in living cells;(ii) measurements of biogenic amines and amino acids in brain tissues;(iii) mass spectrometry assays of stable isotopes for kinetic studies of metabolite turnover in both whole brain and in vitro systems;(iv) a Proteomics Sub-core that identifies proteins and peptides as well as salient post-translational modifications such as phosphorylation;(5) A Cellular Neuroscience Core (Core E) that provides support and advice with regard to (i) cytoarchitectural analysis, (ii) cell culture, and (iii) optical imaging of circuit function in slice preparations using voltage sensitive dyes;(6) A new Neuroimaging Core (Core F) that supports a variety of in vivo neuroimaging methods in humans and animal models, including (i) MRI, (ii) PET, and (iii) MEG. The investigators have modified each core in response to feedback from our users since the 2004 renewal. The IDDRC services more than 100 NIH-funded projects with an aggregate value of >$12 million per year (>$1.5 million from NICHD). The Center includes an excess of 70 Penn faculty at 15 departments at the Schools of Medicine, Veterinary Medicine, Nursing, the Wistar Institute, and the College of Arts and Sciences.